Case IH 1980-02 - UCM – UCM: Vehicle controller loss of communication with rear pilot head #6

The tractor's control module has lost CAN bus communication with the electro-hydraulic actuator (pilot head) that controls the #6 rear remote valve. When a pilot head fails internally, it can short or disrupt the CAN bus network, causing a loss of communication.

• MAGNUM AFS Connect
• Magnum AFS Connect models (180, 200, 210, 220, 240, 250, 280, 310, 340, 380)
• Puma 150, 165, 175, 180-260 CVX, 185, 200, 220, 240
• Steiger / Quadtrac 350, 370, 400, 420, 450, 470, 500, 580
• Optum 270, 300

1. 1

   Isolate the CAN Bus by unplugging the electrical connector specifically at the #6 rear pilot head.

2. 2

   Turn the key on and check if the rest of the remote valves and CAN bus modules come back online. If communication is restored, the #6 pilot head has failed internally.

3. 3

   If unplugging the module does not restore communication, inspect the wiring harness leading to the #6 pilot head for physical damage, corrosion, or broken CAN wires.

1. 1

   Locate the Valve

   Identify the #6 rear remote valve on the rear hydraulic valve stack. The pilot head is the electronic actuator mounted directly on top of the valve body.

2. 2

   Disconnect Power

   Turn off the tractor and disconnect the electrical harness from the #6 pilot head.

3. 3

   Remove the Pilot Head

   Unbolt and remove the faulty pilot head assembly from the main remote valve body.

4. 4

   Install the New Part

   Mount the replacement pilot head onto the valve body and torque the fasteners to OEM specifications. Reconnect the electrical harness.

5. 5

   Reassign and Calibrate

   After replacing a pilot head, you must use the tractor's display monitor (or dealer diagnostic tool) to reassign the valves and perform a valve calibration procedure so the UCM recognizes the new pilot head.